commonality

possession of common features or attributes
--Webster's Collegiate Dictionary, 10th Edition

more specifically,

the extent to which people share similar cognitive mappings,
and thereby share similar psychological processes and similar subjective experience
--Practical Magic, NLP Axioms

people who supply software requirements and
people who design software solutions

need ways to share and compare their internal constructions as conceptual models
esp. their concepts of value, quality, function, and form